FRTU  FeederTerminal Unit

DTU  Distribution Terminal Unit

RMU  Ring Main Unit

• Modular Design of Hardware 

• Wide adjusting ranges of three-remote capacities

• More alternatives of software logic

• Ensurence of security （62351）

• More kinds and quantities of communication interfaces and signal interfaces 

• Smaller size and more ways of installation

• Better adaptability to severe environment

• AC/ DC sampling.
• Telemeter and telecontrol. Various sensors including transformers, digital sensors and etc can be linked to the device.
• Detecting the faults of feeder.
• Three-step protection against over currents and short circuits.
• Two-step protection of zero-sequence currents.
• Secondary reclose with three-phase switches and blocking functions.
• Accelerated protection after over current.
• Fault-detecting Functions among various branches and boundaries.(watchdog)
• Fault detecting based on voltage model or voltage-time model. Comprehensive and self-adaptive fault detecting in  load-switch model.
• On-site/remote operations of the switches. The status of the switches can be indicated by the signal lights.
• Parameters can be input on the interface with strict anti-error and anti-misinput functions.
• Power monitoring. Online managements of the batteries.
• Both on-site and remote maintenance can be achieved.
• The device support various protocols including IEC60870-5-101、IEC60870-5-103、IEC60870-5-104 and etc.
• Self check,mutual check and false alarm. Overall alarm information will be shown in the system and indicated by the LED lights on the panel of main control unit.
• A fault-indicating light of the feeder is fixed outside the cabinet for line patrol.
• Various communication modes can be supported including EPON, optical fiber Ethernet, double-loop self-repaired optical fiber Ethernet, public / private network, radio station, power line carrier and etc.
• The outside structure is designed compactly in divided modular. The pluggable terminals are easy to use and maintain.
• Industrial-class quality. It can adapt to a wide temperature range and has anti-magnetic, shockproof, damp-proof and lightning-proof functions.

• Remote monitoring and control.
• Collecting and processing line faults.
• Diagnosis and treatment of grounding faults.
• Power metering.
• Anti-stealing function.
• Power IOT and etc.

Application Introduction

With complex working environments, large scales of circuits, wide varieties of equipment, traditional medium-voltage distribution network (10kV ~ 35kV) plays a significant role in power transmission, requiring high reliability and stability to guarantee the safety. Compared with high-voltage transmission networks, medium-voltage distribution lines can be more widely applied in automation industries. The transmission lines can be divided into buried cables and overhead types.FRTU（DTU）can collect data, record power consumption, control remotely, solve the faults on site and forward communications in switch stations, power distribution rooms, RMU and box substations utilizing buried cables, achieving automation and intellectualization of distribution networks.

Automatic equipment in power distribution should be designed with smaller size, more functions, higher reliability and safety, better operability and lower costs due to complex environments, large geographic span and wide equipment varieties involved. DF1725IED meet these requirements perfectly. 

Composition and features of system

The functions and power capacity of DF1725IED can be flexibly adjusted according to the application environments.

Installation

Two ways of installation

First, the device can be attached to the instrument bay in the switchgear.

Second, it can be fixed in an independent cabinet with the height from 70cm to 226cm. IP65 cabinet with higher levels of protection is optional in severe environment.

Operation

DF1725IED is compatible with general maintaining software. Maintenance staff can debug various devices from FRTU to RTU using standardized operational software.It can be repaired by maintaining the cables, remotely accessing the channels, maintaining locally and wirelessly. LCD panel is optional for data view and on-site operations instead of external PC and mobiles. 

DF1725IED can be attached either internally or externally to the RMU.

The image below shows the device installed to FRTU cabinet with high protection levels outside the RMU. 

Other

The product has gotten the certificates of general and special type test and IEC62351 test report in a variety of countries. Please contact technical support staff for relative documents.

Previous projects

AJ-RPDRP projects in India.More than 7000 FRTU devices are installed in tens of cities among five states in India.